Billet grinding apparatus



V- 1955 A. E. HAMILTON BILLET GRINDING APPARATUS 2 Sheets-Sheet 2 FiledDec. 4, 1953 r M E R. M m. T WE T n 0 6 n E W b. L a U v m L Qh r0United States Patent ee BILLET GRINDING APPARATUS Alfred E. Hamilton,Pittsburgh, Pa. Application December 4, 1953, Serial No. 396,282

8 Claims. (Cl. 51-33) My invention is particularly suitable for use inthe grinding of steel billets, but can, of course, be used in grindingarticles of other shapes and materials. My invention is a modificationof the structure shown in my Patent No. 2,442,042.

One object of my invention is to provide a simplified form of apparatusfor grinding the opposite faces of billets with uniformity, even thoughthe sides to be surfaced do not extend in true planes or straight lines.

Another object of my invention is to provide improved means for mountinggrinding wheels that are oppositely disposed to one another; which areyieldably urged toward one another against opposite sides of a workpiece, and which are provided with a common stop device which limits thedistance which they may move toward each other independently ofdeviations of work piece surfaces.

Still another object of my invention is to provide an improved manner ofimparting vertically reciprocable movements to a grinding Wheel (or apair of grinding wheels) while in operative engagement with the sides ofwork pieces, while constantly rotating the grinding wheel and forsimultaneously imparting tilting movements to the grinding wheel about avertical axis that is transverse to the axis of rotation of the wheel.

As shown in the accompanying drawings, Figure 1 is a vertical crosssectional view of the grinding apparatus of Fig. 3;

Fig. 2 is a view showing apparatus for conveying the billets one-by-oneto the feed rolls for the machine;

Fig. 3 is a view taken on the line IIIIII of Fig. 1;

Fig. 4 is a partial plan view of certain of the feed rolls of Fig. 3;

Fig. 5 is an enlarged side view of the ratchet feed mechanism of Fig. 3;

Fig. 6 is a view of that portion of the machine as shown in Fig. 1,whereby oscillation of the grinding wheels is eifected, and

Fig. 7 shows a manner in which the billets may be automatically given aquarter turn when passing from one grinding machine to the next machine.

As shown more clearly in Fig. 2, billets 10 are conveyed one-by-one by aconveyor 11 to a feed table 12 that rotatably supports feed rollers 13which advance the billets to a feed roller 14 that is intermittentlyrotated by a pawl 15 whose teeth engage teeth of a ratchet wheel 15a ona shaft 16 to which the roller 14 is secured. The pawl 15 (Fig. 5) ispivotally mounted on a crank arm 17a that is oscillated by a rocker arm17 pivotally mounted on the feed table. Downward movement of the rocker17 under the action of gravity is limited by an adjustable stop screw18.

When the free end of the rocker arm 17 is raised as will be hereinafterdescribed, it will cause the pawl 15 to rotate the feed roll 14 onestep. Whether this step is for a one-tooth pitch distance of the ratchetwheel, or more, depends upon the setting of the stop screw 18. The roll14 has a sprocket drive connection 19 with the next succeeding feed roll13, and the rolls 13 of the train of rolls 2,722,087 Patented Nov. 1,1955 are all driven through similar sprocket chains 19, to therebyadvance the billets to the grinding wheels. A spring-pressed roller 21yieldably holds the billets snugly against the roll 14, a pair ofsprings 22 and adjusting screws 23 being provided above the bearings 24of the roller 21, for this purpose.

A housing 25 that carries the bearings for the roller 21 has pairs ofarms 26 and 27 secured thereto. A supporting roller 28 is journaled inthe bracket arms 26, and a roller 29 is journaled on the arms 31 thatare pivotally supported by the arms 27. The roller 28 serves tovertically support the billet as it passes the feed roll 14, and theroller 29 serves as a hold-down, urged by a spring 32, to steady thebillets against chattering movements in vertical directions.

The billets are advanced step-by-step between a pair of grinding wheels33 that are journaled in hanger arms 34 which, in turn, are pivotallysupported at their upper ends upon a cross head 35 that moves alongvertical slideways 35a. The grinding wheels are driven by electricmotors 36 whose casings are rigidly connected to the hanger arms 34 andtherefore will oscillate along with the hanger arms, about the pivots37. Belt drives 38 are mounted on grooved pulleys for the grindingwheels and the motors respectively, the pulleys being of varyingdiameters so that the belts can be shifted from certain grooves to othergrooves as may be required for changes in driving speed.

The grinding wheels are held against the work pieces 11 by apiston-and-cylinder arrangement at 39 to which air pressure is suppliedthrough flexible hose connections 41. The cylinders at 39 are pivotallyconnected to the cross head 35, and their piston rods 42 are pivotallyconnected to the hangers 34.

The distance to which the grinding wheels may be moved toward oneanother by the pistons is controlled by a shaft 43 that has threadedconnection with one of the hangers 34 and has a boss 45 that seatsagainst the other hanger, so that the grinding wheels cannot be movedtoo far inwardly by their pistons, thus avoiding excessive grinding ofthe billets.

The cross head 35 is reciprocated vertically by an electric motor 46that, through reduction gearing at 47, rotates a crank disc 48 which,through a link 49, is connected to a rocking lever 51 that is pivotallysupported upon the top of the frame and is connected through links 52 tothe cross head. The disc 48 is provided with a plurality of holes 53,whereby the link 49 can be connected thereto at adjusted positions, tothereby vary the length of vertical stroke of the cross head 35.

The billets are advanced step-by-step by upward movements of an arm 55which is rigidly secured to the cross head 35 and has holes throughwhich pull rods 56 and 57 extend, the two rods being connected by achain or a cable 58 that extends over a pulley 59 which is journaled ona bracket that is carried by the frame of the machine. The rods 56 and57 have knobs 60 and 61, respectively, adjustable thereon, so that whenthe cross head upon its down stroke, for moving the grinding wheelsdownwardly along the vertical faces of the billet 10, the bar 55.canengage the knob 61 to pull the lever 17 upward and cause the pawl toadvance the feed rolls 16 one step. This brings an unpolished portion ofthe billet between the grinding wheels, which portion will be groundupon the next upward stroke of the cross head. This upward stroke mayresult in the knob 60 being raised by the bar 55 to again lift the lever17 and operate the pawl for another slight advance of the billet,thereby again presenting unground surfaces for engagement with thegrinding wheels on their next down-stroke.

Either of the knobs 6061 can be so set that it will not be engaged bythe arm 55, so the billet will be advanced only one step during a cycleof up and down movement of the cross head.

In order to give a slight rocking movement to the grinding wheels,thereby insuring better uniformity of grinding and reducing tendency ofthe abrasive surfaces to become loaded, I mount a guide plate 63 onbracket bars 64 that are secured to vertical frame members 65. The plate63 has an inclined slot 66 through which the adjusting shaft 43 extends.Since the shaft has threaded engagement with one of the hangers 34 andextends through a hole in the other hanger 34, the hangers and the shaftwill be oscillated somewhat during vertical reciprocation of the crosshead 35, thereby rocking the grinding wheels on the vertical faces ofthe work pieces, there being sufficient looseness at the cross head andthe pivots 3'7 to permit of this.

As the billets pass the grinding wheels, they will be verticallysupported by a roller 67 and will pass onto rollers 68 and beneath ahold-down roller 69 that corresponds to the roller 21. The rollers 68can be driven by sprocket chains from the ratchet feed as are the rolls13, or the work pieces can be simply advanced by the pushing force ofsucceeding work pieces as they leave the machine. Spray pipes 70 areprovided for directing water against the grinding edges of the abrasivewheels, so as to avoid floating dust and grit particles.

Although the adjustments of the shaft 43 positively limit the distanceto which the grinding wheels 33 may be moved toward one another, bytheir respective pistons and cylinder, there is, in effect, a floatingsupport for the wheels, since their hangers 34 are pivotally supportedon the cross head. By reason of this arrangement, the sides of a billetthat may be warped somewhat will be more uniformly ground than if eachhanger had a stop shoulder entirely independent of the other shoulderinstead of the stop means (the screw thread and the shoulder 45) forboth hangers being on the single shaft 43. The shaft 43 can be turnedduring operation of the machine to effect adjustments of the hangers 34relative to each other. This is desirable because it permits of quickadjustments to compensate for wheel wear and changes in surfaceconditions of the billets passing through the machine, the operator thusbeing able to provide for proper grinding of the billets.

Also, the stop screw 18 can be adjusted during operation of the machineto vary the distance which the billets are moved at each step.

Since the machine of Figs. 1 and 3 grinds only two faces of the billets,I provide means such as the device of Fig. 7 for turning the billetsone-fourth of a revolution, so that the other two faces of the billetswill be in position for grinding at another station which will havegrinding apparatus like that shown in Figs. 1 and 3.

A trough 79, which is an extension of the trough in which the rollers 68are journaled has a shoulder 71 mounted therein that affords unbalancedsupport for the billets when they enter the trough 70, causing them totip sidewise as in Fig. 7.

I claim as my invention:

1. Grinding apparatus comprising a vertically-reciprocable cross head,means for raising and lowering the cross head in continuously repeatedcycles, a pair of hanger brackets pivotally supported by the cross head,a pair of motors and a pair of grinding wheels carried by the brackets,on parallel horizontal axes, each wheel being driven by one of themotors, in opposed relation to the other wheel, and means actuatedstep-by-step by the cross head, for advancing work pieces between thegrinding wheels, in a direction parallel to their axes and in positionfor the grinding of opposite sides of said pieces.

2. Grinding apparatus comprising a vertically-reciprocable cross head,means for raising and lowering the cross head in continuously repeatedcycles, a pair of hanger brackets pivotally supported by the cross head,a pair of motors and a pair of grinding wheels carried by the brackets,each wheel being driven by one of the motors, on a horizontal axisparallel to that of the other wheel, means for advancing the work piecesbetween the wheels along a path parallel to the wheel axes, and meansfor oscillating the grinding wheels about horizontal axes during thevertical movements of the cross head.

3. Grinding apparatus comprising a vertically-reciprocable cross head,means for raising and lowering the head in continuously recurringcycles, a hanger carried by the cross head, a grinding wheel rotatablysupported on a horizontal axis by the hanger, a motor for driving thewheel, a feeding device for moving work pieces horizontally past thegrinding wheel, means operated through vertical movements of the crosshead for actuating the feeding device step-by-step, and means adjustableto effect said operation selectively, either upon the occurrence of theupward or the downward movements of the cross head, or during both ofsaid movements.

4. Grinding apparatus as recited in claim 3, wherein means are providedfor changing the length of each feeding step.

5. Grinding apparatus as recited in claim 3, wherein means are providedfor changing the length of each feeding step, during operation of themachine.

6. Grinding apparatus comprising a vertically-reciprocable cross head,means for raising and lowering the head in continuously-repeated cycles,a hanger bracket pivotally connected at its upper end to the cross head,a motor carried by the bracket, a grinding wheel rotatably supported onthe lower end of the bracket on an axis parallel to said pivotalconnection and driven by the motor, means carried by the cross head foryieldably urging the lower end of the hanger and the grinding wheel inone direction, a work-supporting device that holds a work piece inposition for engagement by the grinding wheel, during vertical movementsof the cross head, and a guide member that swings the lower end of thehanger and the grinding wheel in a vertical plane that is parallel tothe wheel axis.

7. Grinding apparatus comprising a vertically-reciprocable cross head,means for raising and lowering the cross head in continuously repeatedcycles, a pair of hanger brackets pivotally supported by the cross head,a pair of motors and a pair of grinding wheels carried by the brackets,on parallel horizontal axes, each wheel being driven by one of themotors, in opposed relation to the other wheel, and means actuatedstep-by-step by the cross head, for advancing work pieces between thegrinding wheels, in a direction parallel to their axes and in positionfor the grinding of opposite sides of said pieces, means for yieldablyurging each wheel against one side of the work piece independently ofthe other wheel, and adjustable stop means between the hanger bracketsfor limiting movement of the wheels toward each other, to apredetermined relatively spaced distance.

8. The apparatus as recited in claim 7, wherein said stop means areadjustable during operation of the machine.

References Cited in the file of this patent UNITED STATES PATENTS1,862,277 Moon June 7, 1932 1,966,869 Owen July 17, 1934- 2,082,()20Moon June 1, 1937 2,144,987 Miller Jan. 24, 1939 2,302,120 Hamilton Nov.17, 1942 2,505,815 Wodetzky May 2, 1950 2,640,301 Hill et al. June 2,1953

